To provide computer-based mathematical analysis in support of diagnostic activities in the Nuclear Medicine Department and in collaborating Institutes. Applications include: computerized ECG-gated radionuclide angiocardiography studies of left ventricular performance and dyskinesia; scintigraphic studies of regional myocardial blood flow; pulmonary ventilation-perfusion scintigraphy; functional maps of radionuclide renography; and image processing of scintigraphic data. BIBLIOGRAPHIC REFERENCES: Line B.R., Jones A.E., Crystal R.G., Johnston G.S., and Bailey J.J.: An algorithm for the selection of lung margins in scintigraphic ventilation-perfusion studies. Proceedings of the Sixth Symposium on Sharing of Computer Programs and Technology in Nuclear Medicine, 1976 (in press). Green M.V., Bacharach S.L., Douglas M.A., Line B.R., Ostrow H.G., Redwood D.R., Bailey J.J., and Johnston G.S.: The measurement of left ventricular function and the detection of wall motion abnormalities with high temporal resolution ECG-gated scintigraphic angiocardiography. IEEE Transactions in Nuclear Science,$ 1976 (in press).